In the last ten years, there has been little advancement in the treatment of the aggressive brain cancer Glioblastoma Multiforme (GBM). This research describes the synthesis of a superparamagnetic iron oxide (SPION)-based nanotheraputic complex for use in targeting and killing aggressive mesenchymal GBM cells. The average sizes and magnetic properties of the synthesized SPIONs are tailored via a novel time-controlled approach to a previously described electrochemical reaction. Through this synthetic method, the optimal particle size where maximal thermal energy is released upon stimulation with an external magnetic field was determined to be 21 nm. The nano-complex was further modified to selectively target GBM cells by adding a heterobifunctional poly(ethylene) glycol polymer crosslinked to TWEAK (a GBM targeting peptide). Preliminary investigation with FITC Annexin V/propidium iodide fluorescent probes and transmission electron microscopy revealed biochemical and morphological evidence of both SPION internalization and cytotoxic effects over the course of three hours. Thus, these nano-complexes hold promise as a potential treatment agent for an otherwise untreatable disease.